This invention relates to bindings used to connect a user's boot to sports equipment, particularly, but not exclusively, ski bindings, and more particularly, ski bindings used in Telemark skiing.
Telemark skiing, also called “free heel skiing,” is a type of skiing characterized by what is referred to as a Telemark turn, which is a turning technique. A Telemark ski binding connects a ski boot to the ski only at the toe, as do cross-country ski bindings. While the present invention is particularly useful in overcoming certain problems currently encountered with Telemark ski bindings, after having read and understood the following description, those of skill in the art will readily appreciate that the scope of the invention encompasses step-in style bindings that attach a user's boot to a wide variety of sports equipment.
Prior art binding systems for Telemark skis include a toe portion, such as a toe iron, for maintaining the toe of a ski boot in a fixed position. A tension cable is adapted to be passed around the heel of the boot and coupled to a tensioning mechanism for fixing the boot toe to the toe iron such that during skiing the boot heel and the heel of the skier's foot may be raised vertically away from the ski. The cable may incorporate elastic, spring, or other elements that vary the effective length of the cable whilst maintaining tension against the boot. The cable may also incorporate a tensioning mechanism, for example, a tightening lever. Alternatively, or in addition, the binding may employ other means for varying the length of the tension cable, such as a screw bolt and a co-operating nut.
Often a heel engagement device is mounted on the top of the ski for engaging the heel of the boot. These devices often include a lever configured to engage the heel of the boot and thereby apply tension to the cable. For instance a groove may be formed on the heel of the boot in which the lever sits.
A major drawback common to most prior art bindings is that they require the user to kneel or squat down to close the binding on each foot. Prior attempts to design step-in bindings, which at least theoretically allow the user to close the binding without use of their hands, suffer from numerous drawbacks, such as mechanical complexity, fragility, high cost and unreliability.
Prior attempts have been made to address these deficiencies, but with little success. For example, French Patent 2,824,747 discloses a binding having a heel lever with a rounded surface. When the user applies downward pressure with the ski boot, the rounded surface of the heel lever is pressed against the heel pad or the top of the ski, causing the heel lever to rotate about the axis of the cable, thereby moving into a closed position about the heel of the boot. The advantage of the '747 patent is that the heel lever includes a hook or catching mechanism that maintains the binding in an open position, ready for the user to step-in.
However, the '747 patent has disadvantages. For instance, in deep snow it is liable to become clogged such that the user must first clear the binding by hand (i.e. negating the advantages of the step-in feature), and it suffers from heel instability. These and other drawbacks have resulted in the '747 design not being widely adopted.
Another drawback of prior art bindings is that, due to the freedom of movement of the heel of the boot, aggressive skiers are liable to “pop out” of the bindings or to have the heels of their boots slide out on hard landings. This is referred to as “heel instability” and occurs when the heel of the boot moves laterally in a direction approximately perpendicular to the longitudinal axis of the binding/ski due to the forces experienced by aggressive skiers, for instance when a skier lands a jump.
Accordingly, it is an object of the present invention to provide a step-in binding that is an improvement over existing bindings, particularly with respect to ease of use and providing lateral heel stability.